Characteristics of Dimethyl Ether Oxidation in a Preheated Pt-γ-Al₂O₃ Catalytic Reactor

An experimental study on the catalytic combustion of dimethyl ether under various oxidation conditions through a preheated tubular catalytic reactor filled with a lab-made Pt-γ-Al₂O₃ catalyst is presented in this paper. Both the transient variance of temperature distribution during the ignition process and the stationary results as the reactor reaches stable are delineated. The catalytic reactor is mounted in a tubular furnace to preheat and maintain an isothermal boundary. The reaction profiles and ignition processes are characterized by monitoring the temporal temperature traces, which is the steady-state axial distribution of temperature in the reactor. The average axial reaction temperature for different fuel quantities with various isothermal boundaries of the reactor was also evaluated. During the light-off process, the main exothermal reaction zone shift is found. The results demonstrate that a higher equivalence ratio of reactants produces a higher temperature, resulting in more heat transferring upstream and causes a higher conversion ratio. For the same equivalence ratio, a higher isothermal boundary temperature will result in a higher conversion ratio. The more extended reactor is required in one of the two conditions of a lower equivalence ratio of reactants and a lower isothermal boundary of the reactor. Finally, the energy balance and exergy analysis for the reactor was also performed; the results will be the basis for improving and optimizing designs.